Biggest rims and tires?

There is no issue running 235/35/20 on stock 20" truck rims, plenty of people do it.

I was thinking stock was like 185/75/14. I was way off, haha

I am running 225/30/20s on LTZ wheels with re-indexed torsion bars and a mono leaf rear. It rides a little rough but looks nice IMO...

your truck looks very good.
Do the front tires rub the fenders when you hit bumps? or does it tuck inside when the camber gets negative?

Thanks you should see the before...
There is about enough room to slide your finger (not hand) in between the side of the tire and the fender at this point. It's not touching right now and when I hit bumps they seems the tuck up in ther nice. Still gonna try the drop spindles I have and see what happens. If they rub then I'll just get rid of the spindles.

I ran 15" pathfinder wheels with 29"+ mud tires on my stock height regular cab and it was awesome. Didn't rub anything even when compressed and turning.

So 20 inch wheels will probably fit with the right size tires

So 20 inch wheels will probably fit with the right size tires